Cameras capable of automatic film threading using a film cartridge that contains a filmstrip with a protruding, reduced-width, film leader have been available for a number of years. Usually, to load this type of camera, the film cartridge is manually inserted into a film supply chamber and the protruding film leader is manually placed over a film-exposure backframe opening that is located between the film supply chamber and a film take-up chamber. A sprocket wheel alongside the backframe opening is positioned for one of its teeth to be received in one of successive film perforations in the protruding film leader, to drivingly engage the film leader. When the camera is closed, the sprocket wheel is manually or automatically rotated to advance the protruding film leader into the film take-up chamber and to position the first available imaging section of the filmstrip in a film exposure plane at the backframe opening.
If the protruding film leader is relatively short, the leader's forward tip will not extend to the film take-up chamber when the film leader is manually placed over the backframe opening. Then, rotation of the sprocket wheel in driving engagement with the protruding film leader may cause the leader's forward tip to stub against a rigid, fixed partition wall that separates the backframe opening and the film take-up chamber. Consequently, the film leader may become trapped in the backframe opening, rather than being pushed over the partition wall and into the film take-up chamber. This is more likely to occur when the leader's forward tip is curled rather than flat.
To solve this problem, the partition wall can be supported for pivotal movement to serve as a film deflector (rather than being fixed). When the forward tip of the protruding film leader is pushed against the partition wall, the partition wall is pivoted away from the backframe opening and towards the film take-up chamber to allow the forward tip to be deflected over the partition wall instead of becoming trapped in the backframe opening. A relatively light return spring, which is weaker than the pushing force of the leader's forward tip against the partition wall, returns the partition wall to its original position after the leader's forward tip is advanced over the partition wall. This is shown for example in U.S. Pat. Nos. 3,479,938 issued Nov. 25, 1969, No. 4,530,582 issued Jul. 23, 1985, and No. 4,752,797 issued Jun. 21, 1988.